Fix bug with captured parameters and optimized try-catch.

runtime/vm/flow_graph_builder.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_builder.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/class_finalizer.h"
@@ skipping 3737 matching lines @@
         ASSERT(parameter.owner() == scope);
         if (parameter.is_captured()) {
           // Create a temporary local describing the original position.
           const String& temp_name = Symbols::TempParam();
           LocalVariable* temp_local = new(I) LocalVariable(
               0,  // Token index.
               temp_name,
               Type::ZoneHandle(I, Type::DynamicType()));  // Type.
           temp_local->set_index(param_frame_index);
 
+          // Mark this local as captured parameter so that the optimizer
+          // correctly handles these when compiling try-catch: Captured
+          // parameters are not in the stack environment, therefore they
+          // must be skipped when emitting sync-code in try-blocks.
+          temp_local->set_is_captured_parameter(true);
+
           // Copy parameter from local frame to current context.
           Value* load = Bind(BuildLoadLocal(*temp_local));
           Do(BuildStoreLocal(parameter, load));
           // Write NULL to the source location to detect buggy accesses and
           // allow GC of passed value if it gets overwritten by a new value in
           // the function.
           Value* null_constant = Bind(new(I) ConstantInstr(
               Object::ZoneHandle(I, Object::null())));
           Do(BuildStoreLocal(*temp_local, null_constant));
         }
@@ skipping 517 matching lines @@
   Report::MessageF(Report::kBailout,
                    Script::Handle(function.script()),
                    function.token_pos(),
                    "FlowGraphBuilder Bailout: %s %s",
                    String::Handle(function.name()).ToCString(),
                    reason);
   UNREACHABLE();
 }
 
 }  // namespace dart